PPG Industries (NYSE:PPG) has introduced dual-coat technology that helps dual-pane insulating glass units (IGUs) for residential applications achieve R-5 insulating performance.
The dual-coat technology incorporates one 3-millimeter pane of SOLARBAN(R) 70XL glass on the second (#2) surface of the IGU and one 3-millimeter pane of SUNGATE(R) 500 glass on the fourth (#4) surface, separated by a ½-inch of argon-filled space. The configuration generates a winter nighttime U-value of 0.20, providing insulating performance that is better than or equal to any competing dual-pane IGU on the market.
Paul Bush, PPG manager technical services, performance glazings, said R-5 windows, which by definition have a U-value of 0.20 or less, are being emphasized in federal legislation and adopted in building codes to improve the energy efficiency of residential buildings.
"Window and door manufacturers are looking for glass solutions that, in combination with more energy-efficient sash and frame technologies, help their products achieve R-5 insulating performance," he said. "Our glass solutions enable them to do that."
The dual-coat technology is significant because it enables window and door manufacturers to make better-insulating products without multiple air spaces and panes of glass. Multi-cavity IGUs can complicate the manufacturing process for window and door makers and add to the cost that builders, remodelers and homeowners pay for windows.
PPG's dual-coat, double-pane IGU has visible light transmittance (VLT) of 60 percent and a solar heat gain coefficient (SHGC) of 0.26.